Tractor lag



H. G. BOWKER Nov. 20, 1923 TRACTOR LAG Filed April 15. 1921 z'sheets-sheet B vavv cw/ Harold G -E uwker PatenteclNov. 20, 1923.

UNITED STATES PATENT OFFICE.

HAROLD G. BOWKER, OF CLINTONVILLE, WISCONSIN, ASSIGNOR TO TOPP-STEWART TRACTOR (30., OF CLINTONVILLE, WISCONSIN.

TRACTOR LAG.

Application filed April 15, 1921.

To all whom it may concern:

Be it known that I. HAROLD Gr. Bowman, a citizen of the United States, and resident of Clintonville, in the county of Waupaca and State of Wisconsin, have invented certain new and useful Improvements in Tractor Lags; and I do hereby declare that the following is a full, clear, and exact description thereof.

My invention relates to new and useful improvements in tractor lags. such as are designed to engage the ground surface over which the tractor is propelled, and to form an automatic movable track on which the wheel tread movably rests.

Lags of this type h therto have been usually suspended from the inside of the rim by relief pins which extend over the edges of the tire and thus cause considerable wear thereon, due to side thrust.

One important object of my invention is to provide a lag which shall be suspended directly from the flanged member, which forms the bearing surface for the wheel to which it is attached.

Another object of the invention is to so construct the contacting surfaces of the flanged member and lag, that there will be a true rolling action between them, whereby a minimum amount of wear occurs, and the life of the lag member is thereby lengthened.

With the above and other objects in View, my invention consists of the structural details herein described in connection with the accompanying drawings, in which:

Figure 1 represents a side elevation, partly in section, of a fragment of a wheel with my invention applied thereto.

Figure 2 is a plan View of my invention detached,-as indicated by the line 22 of Figure 3.

Figure 3 is a vertical transverse sectional view on the line 3--3 of Figure 1.

Figure 1- is a view similar to Figure 1, but showing the wheel in a. different position.

Figure 5 is a plan view of the flanged member, which is attached to the periphery of the wheel.

Figure 6 is a plan view of the lag mem ber detached, and

Figure 7 is a vertical sectional view on the line 7-7 of Figure 2.

Referring now specifically to the drawings, the numeral 10 indicates the flanged member which is attached to the periphery Serial No. 461,523.

of the wheel 11. by means of the bolts 12. This member 10 has two teeth 13. extending: the full width of the wheel tread and projecting radially therefrom. The teeth are spaced from each other to form a channel 14, and are connected by a web through which the bolts 12 are secured. The outer surfaces of the teeth are curved, as shown at 15. The profile of th s curved surface, as viewed from the side of the wheel, is a true involute curve struck from the periphery of the wheel as an evolute. Extending later ally from the member 10 are flanges 16, which are continued inwardly to the periph cry of the wheel, and form a continuation, as shown at 17 of the curved surface 15. The lag member 18 is rectangular in shape, and formed with a. rectangular opening which receives the toothed member. the forward and rearward surfaces 19 of the opening being shaped to conform to the curved surfaces 15 of the toothed member. The involute surface 15 cooperates with the rolling contacting surfaces of the lag and the periphery of the wheel. There is no relative sliding between the lag and the periphery of the wheel, due to the involute construction, but there is instead a perfect rolling contact.

The member 18 also has the lugs 20 extending inwardly from the sides of the open ing above the flanges 16, whereby the lag member is retained on the toothed member in position for the latter to roll thereon as the tractor moves along the ground. The under surfaces of the lugs 20 are curved, as shown at 21, so as to permit an easy rolling action between the two members. The lag members are provided with spurs 22, which project into the ground and secure a firm grip therein, as will be readily understood.

It will be understood that in attaching this device to a. wheel, the member 10 must first be inserted in the member 18, with the lugs 20 engaging the flanges 16. The bolts 12 are then secured rigidly t the wheel. The operation of my invention will be clearly seen from Figures 1 and 4. As the tractor moves over the ground, the spurs 22 engage therein, and the toothed members 10 roll in the shoes 18. Since the contacting surfaces are in the form of a true involute curve, the rolling action will operate on the same principle as a gear tooth, which is made in the same manner. Thus there will the shoes may be reversed, thus doublin the llte of the shoe. 'lhere will be no we at all on the tire or rim of the wheel. and when the device is worn out it may be replaced at comparatively little expense.

I claim as my invention:

1. In a device of the character descrilwd, a bearing member having means for securely attaching the same to the outer periphery of a wheel flanges projecting latera ly therefrom, and a lag member having lugs loosely engaging said flanges to retain. said lag member in supporting relation to the bearing member.

2. In a device of the character described, a bearing member having means ltOl' securely attaching the same to the outer periphery of a Wheel, the front and rear ita -es of said member forming curved bearing surfaces, flanges formed on the sides or": \id memher. and a lag member having lugs extending over said flanges to retain said ii'iember in position to engage the bearing surfaces as the wheel revolves 3. In a device of the character described, a bearing member having meaustor securely attaching the same to the outer periphery of a Wheel, the front and rear faces of said member forming conveXly curved bearing surfaces, the profile of each of said curved surfaces being an involute curve, flanges projecting laterally therefrom and a lag member having lugs loosely engaging said flanges to retain said lag member in sunnorting relation to the bearing member.

4;. In a device of the character described, abearing member having means for secure] attaching the same to the outer perinhe of a wheel. flanges projectinglaterally there from, and a lag member having lu s in rolling contact with the upper surf :cof the flanges whereby d lag member is SUPPOlted in position to engage the bearing 1116111" ber.

5. In a device of the character described. abearing member havingineans tor securely attaching the same to the rim of a whceh flanges extending laterally trom said hear ing member and spaced from said rim. a tooth extending outwardly from said bearand a lag member having a transverse portion in engagement with said involute face and having lugs exton ding inwardly and positioned between said rim and flanges.

6. The combination with a wheel rim, oi? means secured to the outer periphery of the rim and having tooth portions, a soclteted shoe member loosely carried by the means ing member and having an involute face.

for rocking inter-engaging tooth and socket co-action therewith, the rocking movements of the shoe member being transverse to the wheel axis.

In testimony that I claim the foregoing I have hereunto set my hand at Clintonville, in the county of Naupaca and State of lVisconsin.

HAROLD G. BOVVKER. 

